/*
 * Delta mp3 player
 * Firmware V0.1 CC http://www.lestmar.com/
 * This software is licensed under Creative Commons 3.0 in the the form of by-nc, wich means 
 * that the use of this code is limited for non-commercial use. Any other use is permitted.
 * The routines used for MMC/SD and mp3 chip are licensed by Raphael Abrahams with different
 * restrictions (please check teuthis.com).
 */

// $Id: lcd_4bits.c 21 2010-07-28 08:38:59Z Tino $

#include "lcd.h"

#byte LCD_LAT	= 	0xF89 // Port A
#byte LCD_PORT	= 	0xF80
#byte LCD_TRIS	= 	0xF92

#byte CTRL_LAT	 	= 0xF8C // Port D
#byte CTRL_PORT		= 0xF83
#byte CTRL_TRIS		= 0xF95


#bit  lcd4_rs = CTRL_LAT.2
#bit  lcd4_rw = CTRL_LAT.3
#bit  lcd4_e 	= CTRL_LAT.4

#bit  lcd4_t_rs = CTRL_TRIS.2
#bit  lcd4_t_rw = CTRL_TRIS.3
#bit  lcd4_t_e 	= CTRL_TRIS.4


#bit busy_flag = LCD_PORT.7

static void lcd_post3();
static void lcd_busy();


#define PIPE_LEN 70

struct lcd_pipe_item {
	int1 cmd;
	char data;
};

struct lcd_pipe_item pipe[PIPE_LEN];

int pipe_i=0;
int pipe_f=0;

int1 lcd_full()
{
	return (((pipe_f+1) % PIPE_LEN) == pipe_i);
}

int1 lcd_empty()
{
	return (pipe_f == pipe_i);
}


void lcd_pushcmd(char d)
{

	pipe[pipe_f].cmd=1;
	pipe[pipe_f].data=d;
	pipe_f = (pipe_f+1) % PIPE_LEN;
}

void lcd_pushchar(char d)
{

	pipe[pipe_f].cmd=0;
	pipe[pipe_f].data=d;
	pipe_f = (pipe_f+1) % PIPE_LEN;
}



void lcd_pop()
{
	static int count=0; 

	if (pipe_i != pipe_f)
	{
		struct lcd_pipe_item data;

		data = pipe[pipe_i];

		if( data.cmd && (count>0)  )
			--count;
		else {
			if( data.cmd )
			{
				lcd_putcmd(data.data);
				count=3;				// Ensure at least x cycles between commands
			}
			else
			{
				lcd_putchar(data.data);
				if( data.cmd > 0)
					--count;
			}

			pipe_i = (pipe_i+1) % PIPE_LEN;
		}
	}	
}		

#if 0

int lcd4_test_busy() {
    char s = 0;
	int i;



    LCD_TRIS |= 0x0F;
    lcd4_rs = 0;
    lcd4_rw = 1;
	for(i=0;i<2;i++);
    lcd4_e = 1;
	delay_cycles(1);
	s=busy_flag;
    lcd4_e = 0;

	if( s == 1)
		check_cond(1);		

    lcd4_rw = 0;
    LCD_TRIS &= 0xF0;

}

#endif


static void lcd_post3()
{
    lcd4_rs = 0;
    lcd4_rw = 0;
    LCD_LAT = 0x3;
    lcd4_e = 1;
    lcd4_e = 0;
}



void lcd_init() {

    lcd4_t_rs = 0;
    lcd4_t_rw = 0;
    lcd4_t_e = 0;

    lcd4_rs = 0;
    lcd4_rw = 0;
    lcd4_e = 0;

	LCD_TRIS &= 0xF0;
	LCD_LAT &= 0xF0;


	delay_ms(15);
	lcd_post3();
    delay_ms(5);
	lcd_post3();
    delay_ms(1);
	lcd_post3();
	delay_ms(1);
	lcd_post3();
	delay_ms(1);


    lcd_putcmd(0x28); // 8-bit mode 0x28
	delay_ms(1);
    lcd_putcmd(0x8); // Display off 0x8
	delay_ms(1);
    lcd_putcmd(0xC); // Display on, curs.off, no-blink, 0xC
	delay_ms(1);
    lcd_putcmd(0x6); // Entry Mode 0x06
	delay_ms(1);
    lcd_putcmd(0x1); // ?
	delay_ms(1);
}

static void lcd_busy() {
    char s = 1;
    int i;



    LCD_TRIS |= 0x0F;
    lcd4_rs = 0;
    lcd4_rw = 1;


    for (i=0;i<5;i++) {
			
#asm
			NOP
#endasm


			/* delay_cycles(10);	// 50ns */
    		lcd4_e = 1;
#asm
			NOP
#endasm
			/*delay_cycles(1); */
        	s = busy_flag;
        	lcd4_e = 0;
#asm
			NOP
#endasm

        if (s)
        	break;		        
    }
    lcd4_rw = 0;
    LCD_TRIS &= 0xF0;

}

void lcd_putcmd(unsigned char c) {

    lcd_busy();
    lcd4_rs = 0;
    lcd4_rw = 0;
	LCD_LAT &= 0xF0;
	LCD_LAT |= c >> 4;
	lcd4_e = 1;
	lcd4_e = 0;

	LCD_LAT &= 0xF0;
	LCD_LAT |= c;
	lcd4_e = 1;
	lcd4_e = 0;
}


void lcd_clear() {
    lcd_putcmd(0x01); 	// Clear Screen
	pipe_i=0;			// Empties the lcd buffer
	pipe_f=0;

}

void lcd_putchar(unsigned char c) {


    lcd_busy();
    lcd4_rs = 1;
    lcd4_rw = 0;
	LCD_LAT &= 0xF0;
	LCD_LAT |= c >> 4;
    lcd4_e = 1;	
    lcd4_e = 0;

	LCD_LAT &= 0xF0;
	LCD_LAT |= c;
	lcd4_e = 1;
	lcd4_e = 0;

}